<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<li>aaa</li>
<li>bbb</li>
<li>ccc</li>
<script>
   var lis = document.getElementsByTagName('li');
   console.log(lis);


</script>
</body>
</html>